Information regarding signature analysis
Please note that signotec as the manufacturer cannot provide any legal advice. The following information serves to provide better understanding of the technical and specialist topics, but cannot substitute legal advice.
General information
Signatures can be compared in detail on the basis of their biometric features.
The nature and importance of the matches established between the executed handwriting and the reference handwriting material lead to a conclusion that is conveyed as a statement of probability within a hierarchical scale. In addition to a neutral level (“even chance”), a distinction is made between five clear, verbal assessment levels with increasing relevance.
Using the scale of probability, the respective subjective degree of certainty on the part of the handwriting expert with regard to the probability of theories concerning the respective origin can be arranged in order:
almost certainly
very highly likely
highly likely
likely
quite likely
even chance, cannot be determined
Automatic verification of signatures
Signatures are verified mainly via dynamic features, although signotec carries out a unique combination test involving dynamic and static parameters when comparing signatures. Visual aspects are checked on the static side. The statistical parameters are composed of information from a binary image. Here, the optical impression of a signature is checked through horizontal and vertical vector formation using pattern recognition.
Extraction and compression of individual features
Confirmation of rejection or unknown identity based on a user-defined set of previously collected references
Saving of references in a database
Evaluation of biometric characteristics
Immediate evaluation of classification and identification routines
General remarks on signature analysis
The comparative study of handwriting is based on the empirical fact that handwriting, as a graphic externalization of a writing action, is more or less unmistakable when comparing different people under normal conditions and that a person’s handwriting remains relatively stable over time. The specific configuration and variation of graphic features determine the degree of individual character.
The uniqueness of its character makes handwriting important as material evidence in the context of authenticity and authorship checks since it can directly identify its author. Handwriting has the same evidentiary value as the features of a fingerprint, for example.
Conclusions as statements of probability
The hypothesis-led interpretation of the findings made in a comparative analysis of handwriting is based on the intrinsic value of the graphic consistencies and/or deviations identified.
Differences between handwriting that is being analyzed counteract identification if they cannot be explained (for example, as a result of disguise or other external or internal factors involved in its creation). In order to prove that the author is one and the same person, there must be consistencies in terms of significant feature configurations that are sufficiently multifaceted overall and in which the individual features are specific enough. Firm proof cannot be provided in every case.
Whether and to what extent an authorship statement is possible depends not least on the coverage of the writing in question (scope, graphic complexity and individual character) but also on how representative the comparative handwriting material is. Occasionally, inadequacies in the handwriting material lead to restrictions in terms of meaningful content or prevent a coherent conclusion altogether.